1. Field of the Invention
This relates to lubricant compositions and, in one of its aspects, relates more particularly to lubricant compositions having improved dispersancy and antirust properties in performing their functions. Still more particularly, in this aspect, the invention relates to lubricant compositions in the form of lubricating oils and grease containing additives effective for improving dispersancy and antirust properties.
2. Description of the Prior Art
Prior to the present invention, commercially available alkenylsuccinimides functioning as dispersants have been incorporated into lubricant compositions. In preparing these alkenylsuccinimides dispersants, polybutenylsuccinic anhydrides are employed. The resulting product is of relatively low molecular weight, non-acidic, and effective as a dispersant only at relatively low temperature. In this respect, pertinent prior art discloses the reaction of internal amino groups with succinic anhydride, as in U.S. Pat. No. 3,445,386 of reaction between succinic anhydride and polyamines as in U.S. Pat. No. 3,172,892. These references, however, do not suggest a specific dispersancy and antirust improvement obtained from the use of the products of the present invention, in lubricating compositions. Also, high molecular weight succinimides and amides are disclosed as the art as dispersants for example in U.S. Pat. No. 3,219,666. But these have poor high temperature and antirust properties and also are lower in molecular weight than the products of the present invention.